The cAMP receptor protein (CRP) plays a key role in transcription as a positive regulatory element via cAMP dependent DNA binding. The proposed research will investigate the role of CRP structure and function for cAMP and DNA binding as follows: 1. Role of C-termini in DNA binding; 2. Effect of cNMP in stability of CRP and alpha CRP (cAMP binding core); 3. Role of SH and lysyl groups; 4. Photoaffinity labeling of cAMP binding site; 5. Isolation of DNA binding region of CRP and reconstitution using alpha CRP. BIBLIOGRAPHIC REFERENCES: Eilen, E. and J.S. Krakow, The cAMP Receptor Protein of E. coli Studies on Proteolysis and Sulfhydryl Modification. Fed. Proc. 35, 1385 (1976). Pampeno, C. and J.S. Krakow, Crosslinking of the cAMP Receptor Protein of E. Coli by Ortho-Phenylenedimaleimide as a Probe of Conformation. Fed. Proc. 36, XXX (1977).